This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. In this project, we plan to validate a new biomarker (adiabatic T1[unreadable] and T2[unreadable]) measured non-invasively in the substantia nigra MRI as a means to achieve statistical separation between Parkinson's diseased (PD) patients from control subjects. The novel adiabatic T1[unreadable] and T2[unreadable] MRI relaxation methods proposed here for the measurement of neuronal deficiency may provide useful insights into the pathogenesis of neurological disorders, in particular PD. We demonstrated that the T1[unreadable] relaxation measurements provide direct information about the fundamental dynamic parameters of the water spins in different areas of the brain. We show that the change in density of neurons and their projections is reflected in the tumbling of the water spins. This suggests that T1[unreadable] measurements can potentially be used to quantify the neuronal loss in the SNc of PD patients, as well as likely other neurodegenerative conditions. The T1[unreadable] measurements provide unique information as compared to conventional T1 MRI due to the sweep of the effective magnetic field during the adiabatic pulses used for the measurements. Further studies will be warranted to confirm the applicability of our technique to additional neurodegenerative disease models, however we expect that this technique will prove capable of detecting cell loss in any given brain region of interest.